Pryor and colleagues have written a very interesting article [1]; however, their data on sensitivity and specificity for each of the three diagnostic outcomes (significant disease, severe disease, and left main disease) are subject to verification or work-up bias. Their study sample included 1030 patients, but diagnostic outcomes were verified on only the 168 patients who subsequently had cardiac catheterization within 90 days. Because patients who “tested” positive (based on history and physical examination data) were more likely to have the gold standard evaluation (cardiac catheterization), the reported sensitivities are probably falsely high, and the reported specificities are probably falsely low.